1. Field of the Invention
The present invention relates to the processing of fish fillets in preparation for marketing. More particularly, the invention relates to a method and apparatus for sorting and trimming fish fillets once they have been removed from the fish body and the skin removed from the flesh.
At present, the final processing of fillets is accomplished by loading the individual fillets either mechanically, by hand or a combination of both, onto a moving conveyor belt or candling table. The candling table-conveyor moves the relatively uniformly placed fillets past an inspection station for removal of substandard pieces and onto a discharge point where the fillets are collected for further handling e.g. packaging, freezing, or shipping. An inspector simply removes fillets which have any defects such as adhered pieces of skin, bones or any other blemish. As can well be appreciated, the skinless fish fillets at this point are a very expensive product because of the multiple processing steps they have gone through. Since the fillets are on a moving conveyor table, the inspector does not have an opportunity to remove and trim the unwanted portions from the fillets and hence the entire fillet is diverted from the conveyor for some other subgraded use. The commonly practiced processing method involves removing the blemished fillets from the conveyor table and depositing them into a discharge chute where they are collected and utilized for a product known as "surimi" which is a minced or ground substance used as a food additive. The fillets thus discarded must be sold at a price which is ofttimes only 30-50% of the going price for the prime fillets. It can well be appreciated, from the amount of fish processed in a single shift, that substantial losses are experienced in this final processing phase. The present invention provides a fillet trimming device which cooperates with the moving conveyor table to enable the inspector to manipulate and trim each blemished fillet without interrupting the product flow and without removing the fillet from the table. The method provides for the trimming of the blemished fillets in a manner such that the majority of the fillets continue as a prime product and only the blemished portion of the fillet is diverted to the surimi chute.
2. Description of the Prior Art
It is well known in the prior art to utilize rotary cutting blades for severing the muscle flesh of fish either initially to separate the fillets from the fish body or for the purpose of dividing or sectioning the fillet once it is removed. These prior art devices, however, involve the use of power driven cutting blades for severing the fish flesh which is supported and moved along by the conveyor device. One such example is the U.S. Pat. No. 5,061,221 to Holsuter et al which discloses a rather sophisticated device for sectioning or dividing fish fillets. In this apparatus, circular driven cutter blades are selectively positionable and activated for rotation to divide the fillets according to the desired geometric or volumetric properties. This apparatus contemplates the use of video cameras for assessing the properties of the irregular fillets and the use of a computer program for controlling the power driven knives.
U.S. Pat. No. 5,149,297 to Braeger et al; U.S. Pat. No. 2,140,575 and U.S. Pat. No. 2,110,416, both to E. David et al are examples of the use of power driven circular cutting blades for severing fish flesh to remove the fillets or sides from the fish. The rotary cutting blades in these patents are independently driven and maintained out of contact with any conveying device. U.S. Pat. No. 2,712,153 to Bergland discloses an alternative rotary fish cutting device utilizing power driven circular saws for the purpose of sectioning and boning the fish. U.S. Pat. No. 5,033,164 discloses the combined use of a driven circular filleting blade and mechanism for removing the dark colored flesh from the fish by a pressure process.